The delivery of therapeutic to a target site is an oft-repeated procedure in the practice of contemporary medicine. Therapeutic may be delivered to a target site through direct injection as well as through implants that somehow carry the therapeutic. Implants that are used to deliver therapeutic may serve several purposes including reinforcing fatigued lumens and bridging ruptured vessels. In each of these cases the therapeutic being delivered may not only facilitate the short term healing associated with the introduction of the implant, but may, also, provide long term delivery of therapeutic to the surrounding areas.
One example of an implant is an expandable stent. Expandable stents are tube-like medical implants designed to support the inner walls of a patient's lumen. They can be self-expanding or, alternatively, may require external forces to expand them. In either case they are often deployed through the use of a catheter of some kind.
Because of the direct contact of the stent with the inner walls of the lumen, stents have been coated with various compounds and therapeutics to enhance their effectiveness. When this coating is haphazardly applied or has somehow been removed during the stent's manufacture or delivery the stent's effectiveness can be compromised because a uniform dosage of therapeutic from the coating of the stent to its surroundings may not be plausible.